塞内加尔西部农村社区迪埃洛 1990 年至 2012 年疟疾的兴衰：一项 22 年的纵向研究。

The rise and fall of malaria in a West African rural community, Dielmo, Senegal, from 1990 to 2012: a 22 year longitudinal study.

机构信息

Institut de Recherche pour le Développement, Laboratoire de Paludologie, Dakar, Sénégal.

Institut Pasteur de Dakar, Département d'Epidémiologie, Dakar, Sénégal.

出版信息

Lancet Infect Dis. 2014 Jun;14(6):476-88. doi: 10.1016/S1473-3099(14)70712-1. Epub 2014 May 6.

DOI:10.1016/S1473-3099(14)70712-1

PMID:24813159

Abstract

BACKGROUND

A better understanding of the effect of malaria control interventions on vector and parasite populations, acquired immunity, and burden of the disease is needed to guide strategies to eliminate malaria from highly endemic areas. We monitored and analysed the changes in malaria epidemiology in a village community in Senegal, west Africa, over 22 years.

METHODS

Between 1990 and 2012, we did a prospective longitudinal study of the inhabitants of Dielmo, Senegal, to identify all episodes of fever and investigate the relation between malaria host, vector, and parasite. Our study included daily medical surveillance with systematic parasite detection in individuals with fever. We measured parasite prevalence four times a year with cross-sectional surveys. We monitored malaria transmission monthly with night collection of mosquitoes. Malaria treatment changed over the years, from quinine (1990-94), to chloroquine (1995-2003), amodiaquine plus sulfadoxine-pyrimethamine (2003-06), and finally artesunate plus amodiaquine (2006-12). Insecticide-treated nets (ITNs) were introduced in 2008.

FINDINGS

We monitored 776 villagers aged 0-101 years for 2 378 150 person-days of follow-up. Entomological inoculation rate ranged from 142·5 infected bites per person per year in 1990 to 482·6 in 2000, and 7·6 in 2012. Parasite prevalence in children declined from 87% in 1990 to 0·3 % in 2012. In adults, it declined from 58% to 0·3%. We recorded 23 546 fever episodes during the study, including 8243 clinical attacks caused by Plasmodium falciparum, 290 by Plasmodium malariae, and 219 by Plasmodium ovale. Three deaths were directly attributable to malaria, and two to severe adverse events of antimalarial drugs. The incidence of malaria attacks ranged from 1·50 attacks per person-year in 1990 to 2·63 in 2000, and to only 0·046 in 2012. The greatest changes were associated with the replacement of chloroquine and the introduction of ITNs.

INTERPRETATION

Malaria control policies combining prompt treatment of clinical attacks and deployment of ITNs can nearly eliminate parasite carriage and greatly reduce the burden of malaria in populations exposed to intense perennial malaria transmission. The choice of drugs seems crucial. Rapid decline of clinical immunity allows rapid detection and treatment of novel infections and thus has a key role in sustaining effectiveness of combining artemisinin-based combination therapy and ITNs despite increasing pyrethroid resistance.

FUNDING

Pasteur Institutes of Dakar and Paris, Institut de Recherche pour le Développement, and French Ministry of Cooperation.

摘要

背景

为了指导从高度流行地区消除疟疾的策略，需要更好地了解疟疾控制干预措施对蚊媒和寄生虫种群、获得性免疫和疾病负担的影响。我们监测和分析了西非塞内加尔一个村庄社区 22 年来疟疾流行病学的变化。

方法

1990 年至 2012 年，我们对塞内加尔迪尔莫的居民进行了前瞻性纵向研究，以确定所有发热病例，并调查疟疾宿主、蚊媒和寄生虫之间的关系。我们的研究包括每天对发热患者进行系统的寄生虫检测的医疗监测。我们每年进行四次横断面调查以测量寄生虫流行率。我们每月通过夜间收集蚊子来监测疟疾传播。疟疾治疗在这些年发生了变化，从奎宁（1990-94 年），到氯喹（1995-2003 年），到阿莫地喹加磺胺多辛-乙胺嘧啶（2003-06 年），最后到青蒿琥酯加阿莫地喹（2006-12 年）。驱虫蚊帐（ITN）于 2008 年引入。

结果

我们监测了 776 名年龄在 0-101 岁之间的村民，共随访了 2378150 人日。昆虫接种率从 1990 年的每人每年 142.5 个受感染的叮咬率上升到 2000 年的 482.6，到 2012 年的 7.6。儿童中的寄生虫流行率从 1990 年的 87%下降到 2012 年的 0.3%。在成年人中，它从 58%下降到 0.3%。在研究期间，我们记录了 23546 次发热病例，包括 8243 次由恶性疟原虫引起的临床发作，290 次由间日疟原虫引起，219 次由卵形疟原虫引起。有 3 人直接死于疟疾，2 人死于抗疟药物的严重不良反应。疟疾发作的发病率从 1990 年的每人每年 1.50 次下降到 2000 年的 2.63 次，到 2012 年的仅 0.046 次。最大的变化与氯喹的替代和 ITN 的引入有关。

解释

结合及时治疗临床发作和部署 ITN 的疟疾控制政策，可以几乎消除寄生虫携带，并大大降低人群中疟疾的负担，这些人群暴露于强烈的常年疟疾传播中。药物的选择似乎至关重要。临床免疫力的迅速下降允许快速检测和治疗新感染，因此在面对不断增加的拟除虫菊酯类药物耐药性时，结合青蒿素为基础的联合疗法和 ITN 具有关键作用。